Simple Specification Test Research Articles

Asymmetry in Ball Kicking Speed between Preferred and Non-preferred Leg in Young Soccer Players

Kicking ability is one of the most important skills in soccer. It is very important to have a good kicking ability with both feet. The main goal of this research was to determine a ball kicking asymmetry (KA) between preferred and non-preferred leg in young soccer players for the U-15 and the U-17 age category. The second goal was to determine differences in kicking asymmetry (KA) between players of different playing positions. 183 young players in U-15 category as well as 87 players from U-17 age category were tested with simple soccer specific test to evaluate kicking velocity (km/h) with preferred and non-preferred leg using Pocket radar. Testing took place on the artificial grass during dry and warm weather and ball was kicked while stationary at the 11-m spot. Results obtained with Student’s T-test showed that differences in the maximum kicking velocity with the preferred and non-preferred leg were statistically significant (p≤0.05) in both age groups (90.2±8.8 km/h /78.5±9.8 km/h for U-15) and (102.7±6.4 km/h /89.5±9.4 km/h for U-17) which confirmed KA is present. Additionally, univariate analysis of variance (ANOVA) showed that there were significant differences in KA between different playing positions in U-17 group (KA=14.57/9.72/14.1 for defenders, midfielders and attackers, respectively). Soccer kicking can be a quality indicator for assessing the soccer kicking ability. By assessing kicking ability, relevant results can be obtained in a fast, and efficient way and can be utilized in the selection process of young talents.

A Simple Specification Test for Models with Many Conditional Moment Inequalities

A Simple Specification Test for Models with Many Conditional Moment Inequalities

Comparing the Effect of Intangible Assets and Macroeconomic Parameters on the Stock Prices in Firms Listed on the Stock Exchange of Iran, Saudi Arabia and Iraq

Comparing the Effect of Intangible Assets and Macroeconomic Parameters on the Stock Prices in Firms Listed on the Stock Exchange of Iran, Saudi Arabia and Iraq

Moment tests of independent components

We propose simple specification tests for independent component analysis and structural vector autoregressions with non-Gaussian shocks that check the normality of a single shock and the potential cross-sectional dependence among several of them. Our tests compare the integer (product) moments of the shocks in the sample with their population counterparts. Importantly, we explicitly consider the sampling variability resulting from using shocks computed with consistent parameter estimators. We study the finite sample size of our tests in several simulation exercises and discuss some bootstrap procedures. We also show that our tests have non-negligible power against a variety of empirically plausible alternatives.

Near Identification of Policy Trade-Offs Using Preference Proxies to Elicit Hidden Information in the Linear Case

This paper shows that neither OLS nor 2SLS can generically identify policy trade offs in the linear case, except under extreme assumptions. Practitioners must be content with near identification and the paper discusses how to choose between these two methods. It shows that a two-stage approach using preference proxies to elicit hidden information can potentially narrow the identification gap and that a simple specification test can be used to assess whether these proxies really contribute to improving identification.

A Simple Specific Functional Test for SCD: VEMPs to High Frequency (4,000Hz) Stimuli-Their Origin and Explanation.

A Simple Specific Functional Test for SCD: VEMPs to High Frequency (4,000Hz) Stimuli-Their Origin and Explanation.

Connection between performance and body sway/morphology in juvenile Olympic shooters

The objective of the study was to examine, via use of a simple specific test, the correlation between body sway and performance in Juvenile Olympic shooters, to compare the differences in body morphology between different shooting modalities and to know if the anthropometric profile of a shooter influences performance. 38 national level juvenile shooters (24 pistol and 14 rifle) who competed at a pistol and air rifle Young Promises Spanish Championship participated in the study. Body sway (measured in terms of movements of the Centre of Pressure (COP): maximum displacements, maximum and minimum average velocities, rotation angles and total areas) and anthropometric data (age, height and weight) were recorded under competition conditions during shooting simulations. Performance was measured in terms of average points per shot. The variables of stress and experience before competition were also considered. The study was observational and descriptive following a cross-sectional design. The results showed that, in the juvenile category, rifle shooters perform better than pistol shooters, but pistol shooters have less body sway. Performance was found to be statistically related to COP displacements, only in pistol shooters. Body weight was found to be related to body sway but not with performance. Body height was found to be related neither with body sway, nor with performance No anthropometric differences have been found to exist between the different modalities (pistol and rifle).

SPECIFICATION TESTING DRIVEN BY ORTHOGONAL SERIES FOR NONLINEAR COINTEGRATION WITH ENDOGENEITY

This paper proposes two simple and new specification tests based on the use of an orthogonal series for a considerable class of bivariate nonlinearly cointegrated time series models with endogeneity and nonstationarity. The first test is proposed for the case where the regression function is integrable, which fills a gap in the literature, and the second test, which nests the first one, deals with regression functions in a quite large function space that is sufficient for both theoretical and practical use. As a starting point of our asymptotic theory, the first test is studied initially and then the theory is extended to the second test. Endogeneity in two general forms is allowed in the models to be tested. The finite sample performance of the tests is examined through several simulated examples. Our experience generally shows that the proposed tests are easily implementable and also have stable sizes and good power properties even when the ‘distance’ between the null hypothesis and a sequence of local alternatives is asymptotically negligible.

Testing for time-invariant unobserved heterogeneity in generalized linear models for panel data

Recent literature on panel data emphasizes the importance of accounting for time-varying unobservable individual effects, which may stem from either omitted individual characteristics or macro-level shocks that affect each individual unit differently. In this paper, we propose a simple specification test of the null hypothesis that the individual effects are time-invariant against the alternative that they are time-varying. Our test is an application of Hausman (1978) testing procedure and can be used for any generalized linear model for panel data that admits a sufficient statistic for the individual effect. This is a wide class of models which includes the Gaussian linear model and a variety of nonlinear models typically employed for discrete or categorical outcomes. The basic idea of the test is to compare two alternative estimators of the model parameters based on two different formulations of the conditional maximum likelihood method. Our approach does not require assumptions on the distribution of unobserved heterogeneity, nor it requires the latter to be independent of the regressors in the model. We investigate the finite sample properties of the test through a set of Monte Carlo experiments. Our results show that the test performs well, with small size distortions and good power properties. We use a health economics example based on data from the Health and Retirement Study to illustrate the proposed test.

Testing Competing Models for Non-negative Data with Many Zeros

Abstract In economic applications it is often the case that the variate of interest is non-negative and its distribution has a mass-point at zero. Many regression strategies have been proposed to deal with data of this type but, although there has been a long debate in the literature on the appropriateness of different models, formal statistical tests to choose between the competing specifications are not often used in practice. We use the non-nested hypothesis testing framework of Davidson and MacKinnon (Davidson and MacKinnon 1981. “Several Tests for Model Specification in the Presence of Alternative Hypotheses.” Econometrica 49: 781–793.) to develop a novel and simple regression-based specification test that can be used to discriminate between these models.

A specification test for discrete choice models

In standard discrete choice models, adding options cannot increase the choice probability of an existing alternative. We use this observation to construct a simple nonparametric specification test by exploiting variation in the choice sets individuals face. We use a multiple testing procedure to determine the particular kind of choice sets that produce violations. We apply these tests to the 1896 US House of Representatives election and reject commonly used discrete choice voting models.

Specification Testing Driven by Orthogonal Series in Nonlinear and Nonstationary Time Series Models

This paper establishes two simple and new specification tests based on the use of an orthogonal series. The paper then establishes an asymptotic theory for each of the proposed tests. The first test is initially proposed for the case where the regression function involved is integrable and the second test is an extended version of the first test for covering a class of non-integrable functions. The finite sample performance of the proposed tests is examined through using several simulated examples. Meanwhile, an application of the second test shows that a second-order polynomial model is more appropriate than a commonly used linear model for modelling the relationship between the United States consumers' consumption expenditure and disposable income over the time period of 1960-2009. Our experience generally shows that the proposed tests are easily implementable and also have stable sizes and good power properties even when the 'distance' between the null hypothesis and a sequence of local alternatives is asymptotically negligible.

Anti-HSP90 autoantibodies in sera of infertile women identify a dominant, conserved epitope EP6 (380-389) of HSP90 beta protein

BackgroundWe earlier reported a simple specific test for detection of anti-ovarian antibodies in infertile women and identified number of specific molecular and cellular targets of which human heat shock protein 90-beta (HSP90 beta) was found to be the most immunodominant. The present study focuses on prediction and validation of the immunodominant epitope/s of this protein using sera from infertile women having anti-HSP90 autoantibodies.MethodsDelineation of the immunodominant epitopes of HSP90 beta was done by using epitope prediction algorithms and 10 peptides (EP1-EP10) were custom synthesized. Their immunoreactivity was measured by ELISA using sera from patients and controls. To determine the most immunodominant epitope, the results were subjected to statistical analysis. The immunoreactivity of the immunodominant peptides were confirmed by dot blots using sera from patients. A rabbit polyclonal antibody against the immunodominant epitope was generated and its immunoreactivity to the parent protein in ovarian extracts as well in oocytes and embryos was investigated.ResultsExperimentally and statistically, peptide EP6 (380-389) seems to be the major antigenic epitope for the serum antibody binding followed by EP1 (1-12) and EP8 (488-498). Predicted 3D structures of these peptides demonstrated that they exist in the loop conformation which is the most mobile part of the protein. Also, analysis of the sequences of HSP90 beta across several species reveals that EP6 peptide forms a part of a well conserved motif. The polyclonal antibody generated to the immunodominant epitope- EP6 confirms similar biochemical and cellular immunoreactivity as seen with the patients' sera having anti-HSP90 autoantibodies.ConclusionsThe decapeptide EP6 is a major immunogenic epitope of HSP90 followed by EP1 and EP8. Knowledge of binding epitopes on the autoantigen is necessary to understand the subsequent pathologic events. The study might generate new tools for the detection of disease-inducing epitopes and a possible therapeutic intervention.

Rapid and simple IgG specific test for the exclusion of heparin induced thrombocytopenia (HIT)

The exclusion of heparin induced thrombocytopenia (HIT) is required for selecting the most appropriate anticoagulation therapy in affected patients. It requires the combination of clinical data with the detection of antibodies directed against platelet factor 4 (PF4) in complex with polyanions (PA) such as heparin. We developed a lateral flow immunoassay (LFIA) for PF4/PA complex specific IgG antibodies based on gold nanoparticles. Unlike most other assays, the initial immune reaction takes place in the liquid phase. The sensitivity of the assay has been adjusted with clinical samples aiming in the reliable detection of sera which are positive in a functional platelet activation assay. Sera from 60 patients with suspected HIT were investigated. LFIA identified correctly all samples (n=20) which were positive in a functional assay (HIPA) and an IgG specific ELISA. It correlated with ELISA, but false positive results were less frequent (7 samples were negative with LFIA and HIPA but positive with ELISA). The LFIA may be a suitable tool for the rapid exclusion of HIT within 10 min.

DETECTION OF FUNCTIONAL FORM MISSPECIFICATION IN COINTEGRATING RELATIONS

A simple specification test based on fully modified residuals and the cumulative sum (CUSUM) test for cointegration of Xiao and Phillips (2002, Journal of Econometrics, 108, 43–61) are considered as means of testing for functional form in long-run cointegrating relations. It is shown that both tests are consistent under functional form misspecification and lack of cointegration. A simulation experiment is carried out to assess the properties of the tests in finite samples. The Dickey–Fuller test is also considered. The simulation results reveal that the first two tests perform reasonably well. However, the Dickey–Fuller test performs poorly under functional form misspecification.

RESET for quantile regression

This paper proposes a simple specification test for quantile regression models. Our test is based on Ramsey’s (J. R. Stat. Soc. B 31:350–371, 1969) RESET (regression specification error test). Comparing to existing nonparametric specification tests, the proposed test does not contain kernel functions and bandwidth parameters and is easy to implement. Although the proposed test is not necessarily consistent against all types of misspecification, simulation results indicate that our test has reasonable size and power properties and can be more powerful than nonparametric specification tests in small samples.

Testing the random walk hypothesis through robust estimation of correlation

This paper uses Monte Carlo simulations to examine the properties of the conventional Pearson and some of the most well-known robust to outliers estimators of correlation in the presence of general heteroskedasticity. We show that the tests of a random walk based on the Pearson autocorrelation coefficient, including the Lo and MacKinlay [1988. Stock market prices do not follow random walks: evidence from a simple specification test. Rev. Financial Studies 1, 41–66] robust form of the variance-ratio test, can be unreliable in the presence of some forms of conditional heteroskedasticity. As an alternative to the Pearson autocorrelation coefficient, we propose the median coefficient of autocorrelation. Our simulation results show that, in contrast to the Pearson autocorrelation coefficient, the median coefficient of autocorrelation is robust to conditional heteroskedasticity. When applied to exchange rate returns, the variance-ratio test based on the median autocorrelation coefficient provides stronger evidence against the random walk hypothesis compared with the Lo and MacKinlay [1988. Stock market prices do not follow random walks: evidence from a simple specification test. Rev. Financial Studies 1, 41–66] robust variance-ratio test.

Fleshing Out the Monetary Transmission Mechanism: Output Composition and the Role of Financial Frictions

Financial frictions affect the way in which different components of GDP respond to a monetary policy shock. We embed the financial accelerator of Bernanke, Gertler and Gilchrist (1999) into a medium-scale Dynamic General Equilibrium model and evaluate the relative importance of financial frictions in explaining monetary transmission. Specifically, we match the impulse responses generated by the model with empirical impulse response functions obtained from a vector autoregression on US time series data. This allows us to provide estimates for the structural parameters of our model and judge the relevance of different model features. In addition, we propose a set of simple and instructive specification tests that can be used to assess the relative fit of various restricted models. Although our point estimates suggest some role for financial accelerator effects, they are actually of minor importance for the descriptive success of the model.

A Systematic Hard- and Soft-Switching Performances Evaluation of 1200V Punchthrough IGBT Structures

The performances of various 1200 V insulated gate bipolar transistor (IGBT) structures for hard- and soft-switching (both the zero-voltage and the zero-current switching) at high temperature and under various test conditions are investigated in detail. A comparison is made between a conventional planar punchthrough IGBT (P-IGBT) using global lifetime control, a trench punchthrough IGBT (T-IGBT) using local lifetime control and a enhanced planar punchthrough IGBT (N-IGBT) also using the local lifetime control process. A simple and effective specific test circuit allows hard- and soft-switching operating modes, and provides also an independent control on the test parameters (load current, clamping voltage, gate resistance, temperature, dead times). It is highlighted that the local lifetime control is very efficient at high temperature reducing especially the turn-off losses. Furthermore, the T-IGBT exhibits very good performances during hard- and soft-switching turn-off, but this is not the case during hard-switching and zero-voltage switching turn-on. Due to its high input capacitance, the hard-switching turn-on losses are relatively high. Regarding the N-IGBT, it presents good performances under hard-switching and also zero-voltage switching. However, like the T-IGBT, its structure has a strong inductance behavior during zero-voltage turn-on increasing the conductivity modulation lag and also the voltage spike leading to high losses. All these data allow to provide useful information for the devices modeling, design, and optimization.

B-type natriuretic peptide (BNP): can it improve our management of patients with congestive heart failure?

Until recently no simple specific test existed for the differentiation of decompensated heart failure from other causes of acute dyspnoea, or to assess the prognosis of patients with severe heart failure or to optimize heart failure therapy in an individual patient. Measurement of B-type natriuretic peptide has become available as an easy-to-per-form bedside test. Several studies have demonstrated it's usefulness in the emergency room to differentiate heart failure from other causes of acute dyspnoea or to guide the complex drug therapy in an individual patient with heart failure. This article gives a short overview on the clinical experience to use BNP-blood levels for the diagnosis and treatment guidance of heart failure.